Season the chicken breasts with salt and pepper. Dip each breast into the beaten egg, then coat with a mixture of breadcrumbs and grated Parmesan cheese.
Heat oil in a large skillet over medium heat. Fry the chicken until golden brown on both sides, about 3-4 minutes per side.
Place the fried chicken in a baking dish. Top each breast with marinara sauce and sprinkle with mozzarella cheese.
Bake in the preheated oven for 10 minutes or until the cheese is melted and bubbly.